CIDR stands for?

• A. AI
• B. Cardiac
• C. Controlled intra-vaginal drug release (progesterone to aid In heat)
• D. DNA structure

Answer: (C)

CIDR is a device used to control when animals come into heat by delivering a hormone in a steady, controlled manner from inside the vagina. It stands for Controlled Internal Drug Release. The intravaginal placement allows progesterone to act to regulate the reproductive cycle, and when the device is removed, progesterone levels fall and animals tend to come into estrus in a predictable window, making timing for breeding or artificial insemination more reliable. That’s why the option describing controlled intravaginal drug release with progesterone to aid in heat fits best. The other choices point to AI, cardiac issues, or DNA structure, which aren’t related to this device or its use.